1. Field of the Invention
This invention relates to a connector, and in particular to a connector forming part of an expandable tubing assembly. The invention also relates to a method of connecting lengths of expandable tubing.
2. Description of the Related Art
WO93\25800 describes expandable tubing defining overlapping longitudinal slots. On expansion of the tubing, by pushing or pulling a mandrel through the tubing, the slots expand to form diamond-shaped apertures. The expansion is accommodated by deformation of the fingers of metal between the slots, this deformation taking place predominantly at the slot ends, and also by circumferential extension of the parts of the tubing wall beyond the slot ends. In expandable tubing developed by the applicants radial expansion is achieved with the parts of the tubing wall between and beyond the slot ends experiencing little if any deformation, these parts being known as the tubing “nodes”.
Arrangements for connecting lengths of slotted tubing are disclosed in WO96\37687 and WO97\21901, the disclosures of which are incorporated herein by reference. Both of these documents describe arrangements in which the end of one length of tubing defines a male coupling portion which is received within a female coupling portion on the other length of tubing and attached thereto.
In another coupling arrangement, the ends of the tubing lengths are received within an external coupling sleeve. However, it has been found that, following expansion, the sleeve contracts radially by a significant extent; this creates a restriction in the bore defined by the tubing.